Conrad Murray Sings Through Interview with Anderson Cooper

Dr. Conrad Murray, in prison for involuntary manslaughter in Michael Jackson's death, literally sings his way through a live phone interview from his jail cell.

Anderson Cooper didn't know what to make of the weird behavior.

Murray sang lyrics, "I'm so sorry for that laddie, he hasn't got a daddy" from Nat King Cole's hit song, "The Little Boy That Santa Claus Forgot."

So why did Murray burst into the melancholy Christmas Song? He said it illustrates how he and Michael Jackson shared painful childhoods.

"He's the little boy that Santa Claus forgot.' That song tells my story. That's how I grew up. I had no Christmases. I had no toy. I had nothing,"

INSIDE EDITION's Paul Boyd spoke to Murray's attorney Valerie Wass, who was in CNN's New York studio during Murray's bizarre performance.

Boyd asked, "How do you explain what appears to be very bizarre behavior during this TV interview?"

Wass replied, "Dr. Murray has told me that neither he nor Jackson could listen to it at Christmas. It brought them both to tears. He talked about the song. It was something--a bond between the two of them."

"The Little Boy That Santa Claus Forgot" was a hit for legendary singer Nat King Cole in 1956.

As Murray struggled to hit the high notes, he said he will refuse to testify in Katherine Jackson's $40 billion wrongful death suit against the concert promoter of the This Is It tour. The trial started this week with jury selection in Los Angeles.